package offer.secnod;

import java.util.Stack;

public class Offer09 {

    /**
     * 构建队列的声明
     */
    public class BuildQueue {
        Stack<Integer> stack1 = new Stack<Integer>();
        Stack<Integer> stack2 = new Stack<Integer>();

        public void push(int node) {
            stack1.push(node);
        }

        public int pop() {
            if (!stack2.isEmpty()){
                return stack2.pop();
            }

            if (stack1.isEmpty()){
                return  -1;
            }

            while (!stack1.isEmpty()){
                stack2.add(stack1.pop());
            }
            return  stack2.pop();

        }
    }


}
